Improved process of treating coal-tar to manufacture roofing-cement



' A. H. PERKINS.

V Treating Coal Tar t0 Manufacture Roofing Cement. No. 36,632. PatentedOct. 7,1862.

IJNITED STATES PATENT OFFIcs-Q A. H. PERKINS, OF JANESVILLE, WISCONSIN,ASSIGNOR TO HIMSELF AND JOHN M. MAY, OF SAME PLACE.

IMPROVED PROCESS OF TREATING COAL-TAR T0 MANUFACTURE ROOFING-CEMENT.

Specification forming part of Letters Patent No. 36,632, dated October7, 1862.

To all whom it may concern;

Be it known that I, A. H. PERKINS, of Janesville, county of Rock, Stateof Wisconsin, have invented a new and Improved Process of TreatingCoal-Tar to Form a Cement for Roofing, Paving, and Coating Purposes; andI do hereby declare that the following is a full and accuratedescription of the same.

Coal-tar in order to be converted into cement requires to be cooked ordistilled until the proper consistency is attained. To perform thisoperation by the old process, expensive boilers and worms were required,reaching in cost several hundred dollars. It also required a fire ofsuch intensity under the boilers that'hard coal only could be used, andbeside this, many days of time were consumed in operating upon a givenquantity of coaltar.

My new process consists in igniting the bulk of coal-tar itself aboutits surface, and at the same time subjecting it to an agitation, thusfeeding the flame and consuming and evaporating the portions necessaryto be disposed of before the proper consistency can be attained.

By my process the use of hard coal or other fuel under the vessel isunnecessary, and a simple plain vessel or boiler may be used, and stillthe oily part of the tar and the water therein be consumed orevaporated, or so much thereof as to reduce the tar to a cement of theproper consistency for roofing buildings, &c., paving streets, whenwooden blocks and timbers are used, for coating woodsurfaces,clothfelting iron, tin, and metals of other kinds, and for analogouspurposes.

In the drawings I have shown several styles of apparatus for aiding inperforming the process; but I do not restrict myself to any particularform of vessel, nor to any particular style of agitator, nor to anyparticular mode of operating the agitator.

A, Figures 1 and 2, represents an oblong vessel with a concave orcylindric configuration in its cross-section. This vessel has an adjustable top, 13, and is provided with a dischargeorifice, a, near itsbottom at one end.

0 is a longitudinal shaft with two wings, D D, which are divided up intoa series of narrow blades, b b, bent in such manner, as shown in thedrawings, as to divide and lift up the bulk of coal-tar in theirmovement through same. Thus the agitation is kept up continually whilethe shaft is kept in. motion. This agitator has its shaft 0 hung inbearings c 0 of the ends of the vessel, and on one end of the shaft acrank-arm, (Z, is formed, so that a rod, 6, may be attached to it andused for rocking or vibrating the agitator in the bulk of tar.

With this apparatus the coal-tar is treated as follows: The tar ispoured into the vessel and set on fire on its surface, and then stirredby the agitator sufficiently to bring all the material suitably incontact with the flame for the purpose of feeding the flame andconsuming or evaporating enough of the oil and water and other articlesmixed with the coal-tar, so that the residue will be of a suitableconsistency for adaptation to the kind of work or purposes required. Forinstance, for a steep roof, very hard; flat roof, quite soft; forcoating wood, or iron, or cloth and felting, medium, or as deemeddesirable and practicable. When it is brought to the proper consistency,the fire is extinguished by closing the top down upon the vessel. If thelid or top should be of wood, its under surface should be thoroughlysaturated or wetted with water when brought down over the flame toextinguish it, in order to obviate scorching or burning of it. Thesubstances may be run off out of the vessel by the orifice a, or removedin any other manner deemed best.

. In Fig. 3 I have shown a common kettle and an agitator in form of ashovel with curved handle, and in Fig. 4 a circular flaring vessel andan agitator in form of a hoe are shown. Vith both of these the processis performed by igniting the tar on the surface and agitatingthe bulk oftar below the flame, so as to bring fresh portions up to the flamecontinuously until the process is completed.

The vessel may be rectangular, cylindric, spherie, conic, or of anyshape desired.

In Figs. 5 and 6 square and oblong vessels are shown.

Some of the advantages of my invention may be summed up as follows:

First. It saves the heavy expenses of boil ers, &c., used in distilling,and by which the business is retained in the hands of a few capitalists.

Second. It saves all fuel other than that in the coal-tar, and that fuelbeing the parts that necessarily must be thrown off or got rid of beforethe tar can be converted into a cement of the proper consistency.

Third. It saves time. A few hours only are needed instead of days, aswith the old method.

Fourth. A greater bulk of cement is made from a given amount ofmaterial, and the product is more durable from the fact of itsvulcanization by flame directly in contact with it.

Fifth. It can be made at any place, and therefore may be made hard orsoft to adapt it to the inclination or flatness of the roof.

Sixth. It saves transportation from the few places where it is now madeby the old process, as by the new process it can be made wherever thework of roofing, 850., is to be done, or at the numerous gas-works inthe country.

I am aware that surface-burning of coal-tar in the manufacture oflamp-black is commonly practiced. I also am aware that in themanufacture of lamp-black by burning coal-tar on the surface attemptshave been made to render the residue of the coal-tar useful for cementpurposes; but as the tar is not subjected to an agitation in eitherprocess, and is allowed to burn sufliciently in a still state to producelamp-black, neither of these processes are the same as mine.

lVhat I claim as my invention, and desire to secure by Letters Patent,is

The new process herein described, of treating coal-tar to form a cementmaterial, for the purposes set forth.

Fitness my hand in the matter of my application for a patent for animproved process of treating coal-tar to form cement for roofs,pavements, 850., this 17th day of June, A. D. 1862.

A. H. PERKINS.

\Vitnesses:

O. E. HARWooD, J OHN THOMSON.

